Single-eccentric link reverse.



v. LAWRENCE. SINGLE ECCENTRIC LINK REVERSE.

APPLICATION FILED APR. 12. I917.

[LMAEL Pmmm Julyz, 1917.

aria-um: 3

VEBNON LAWEENCE, OE MINNEAPOLIS, MINNESOTA.

Application filed April 12, 1917.

To all whom it may concern:

Be it known that I, Vn moN LA RENCE, a citi /,en of the United States, residing at Minneapolis, in the county of Hennepin, State of Minnesota, have invented a new and useful SinglcTEccentric Link Reverse; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same,

The present invention relates to a. single eccentric link reverse for steam enginesand has for its object to provide a device of this character which embodies novel features of construction whereby the link mechanism for reversing the steam valve can be actuated by a single eccentric Further objects of the invention are to provide a single eccentric link motion of thischaracter which is comparatively simple and inexpensive in its construction, which can be used in connection with any conventional type of steam engine and slide valve, which can be easily manipulated, and which will remain locked in an adjusted position.

With these and other objects in view, the invention consists in certain novel combinations and arrangements of the parts as will more fully appear as the description proceeds, the novel features thereof being pointed out in the appended claims.

For a full understanding of the invention, reference is to be had to the following description and accompanying drawing, in which Figure 1 is a side elevation of a steam engine provided with a. single eccentric link motion constructed in accordance with the invention.

Fig. 2 is an enlarged detail view of the single link reverse motion, showing it as detached from the engine.

Fig. 3 is an enlarged sectional view on the line 33 of Fig. 2.

Corresponding and like parts are referred to in the following description and indicated in all the views of the drawings by the same reference characters.

For the purpose of illustration the invention is shown as applied to a conventional steam engine A including a cylinder 1 having a valve chest 2 superposed thereon, the piston rod 3 being connected through the medium of a cross head 4 and pitman 5 to the main crank shaft 6, The eccentric 7 Specification of Letters Patent.

SIN G-LE-EGCENTBIC LINK REVERSE.

Patented July 21, 191-7,

Serial No. 161,501.

for operating the link motion is shown as applied to the main shaft 6 and as surrounded by a strap 8 which is connected by an arm 9 to an ear 10 projecting from one end of the link 11. The link 11 has the usual slotted formation, and is bent longitudinally on the arc of a circle, being provided at its middle point with a pivot ear 12 which is mounted upon a fixed bracket arm or support 13. The link member 11 is thus free to oscillate back and forth upon its pivotal connection with the bracket arm 13, although it is held against sliding.

A block 14 is slidably mounted within the slotted link 11, and a pivot pin 15 extends transversely through the block, said pivot pin being engaged by the bifurcated end- 16 of a connecting rod 16 which is pivotally connected to the valve rod 17 projecting from the steam chest 2. This pivot pin 15 is also engaged by the bifurcated end 18 of a reciprocating shifting arm 18, the opposite end of the said shifting arm being pivotally connected to one arm of a bell crank 19 which is pivoted at 20. The other arm of the bell crank 19 is connected by a link 21 to a reversing lever 22, so that by moving the reversing lever the bell crank 19 can be swung about its pivot point and the block 14; moved to either end of the slotted link 11.

The bifurcated end 18 of the shifting arm 18 is slotted at 23 to receive the slide 15 of the pivot pin 15, springs 21 being in terposed between the ends of the slot and the slide 15 so as to normally hold the slide at the middle of the slot. The shifting arm 18 is thus enabled to have a limited longitudinal movement in either direction inclependently of the block 14. A cam notch 25 is provided in one side of the shifting arm 18, the sides of the cam notch being inclined in opposite directions, and the said notch receiving a, finger 26 projecting outwardly from a spring latch member 27 slidably mounted within the block 14. This latch member 27 is slidable transversely of the block and the nose thereof is adapted to engage a notched seat 28 at either end of the link, thereby locking the block securely in operative position at either limit of its move ment. During the normal operation of the engine the lateral finger 26 of the spring latch 27 is seated within the base of the cam notch 25 with the nose of the latch member in engagement with one of the seats 28.-

hen it is desired to reverse the motion of the engine the lever 22 is manipulated to move the block 14:. Upon the initial movement of the shifting arm 18 the said member moves independently of the block and the finger 26 rides upon one of the sides of the cam shaft 25 to retract the spring latch 27 into inoperative position. The block 14: can then be moved to the opposite end of the link 11, where the spring latch 27 will engage the other notched seat 28. This shifting of the block 1% from one end of the link 11 to the opposite end thereof will reverse the relationship between the steam valve and the eccentric 7 upon the main shaft of the engine, thereby causing the motion of the engine to be reversed. The spring latch member 27 serves to hold the block 1 1 in position at either end of the link member 11, although in reversing the lever 22 to move the block the latch 27 is automatically released.

Having thus described the invention, what I claim as new and desire to secure by Letters Patent, is

1. A single eccentric link motion including a link pivotally supported between its ends, means for oscillating the link about its pivotal support, a block slidably mounted upon the link, means for connecting the block to a valve rod, a shifting arm for moving the block to either end of the link, and latch means for holding the block at either limit of its movement, said latch means be ing operable by the shifting arm.

2. A single eccentric link motion, including a link pivotally supported between its ends, means for oscillating the link about its pivotal support, a block slidably mounted upon the link, means for operatively connecting the block to a .valve rod, a shifting arm having a pin and slot connection with the block and formed with a cam notch, and a spring latch mounted upon the block for looking it at either end of the link, and a finger projecting from the latch and received within the cam notch of the shifting arm whereby the initial movement of the shifting arm will release the latch.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

VERNON LAWRENCE.

Witnesses:

Oscar: BERG, Hans BOYSON.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. O. 

